Synnefo

# Copyright (C) 2012, 2013 GRNET S.A. All rights reserved.

#

# Redistribution and use in source and binary forms, with or

# without modification, are permitted provided that the following

# conditions are met:

#

#   1. Redistributions of source code must retain the above

#      copyright notice, this list of conditions and the following

#      disclaimer.

#

#   2. Redistributions in binary form must reproduce the above

#      copyright notice, this list of conditions and the following

#      disclaimer in the documentation and/or other materials

#      provided with the distribution.

#

# THIS SOFTWARE IS PROVIDED BY GRNET S.A. ``AS IS'' AND ANY EXPRESS

# OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED

# WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR

# PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL GRNET S.A OR

# CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,

# SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT

# LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF

# USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED

# AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT

# LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN

# ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE

# POSSIBILITY OF SUCH DAMAGE.

#

# The views and conclusions contained in the software and

# documentation are those of the authors and should not be

# interpreted as representing official policies, either expressed

# or implied, of GRNET S.A.

"""

Simple and minimal client for the Astakos authentication service

"""

import logging

import urlparse

import urllib

import hashlib

from copy import copy

import simplejson

from astakosclient.utils import \

    retry_dec, scheme_to_class, parse_request, check_input, join_urls

from astakosclient.errors import \

    AstakosClientException, Unauthorized, BadRequest, NotFound, Forbidden, \

    NoUserName, NoUUID, BadValue, QuotaLimit, InvalidResponse, NoEndpoints

# --------------------------------------------------------------------

# Astakos Client Class

def get_token_from_cookie(request, cookie_name):

    """Extract token from the cookie name provided

    Cookie should be in the same form as astakos

    service sets its cookie contents:

        <user_uniq>|<user_token>

    """

    try:

        cookie_content = urllib.unquote(request.COOKIE.get(cookie_name, None))

        return cookie_content.split("|")[1]

    except BaseException:

        return None

# Too many instance attributes. pylint: disable-msg=R0902

# Too many public methods. pylint: disable-msg=R0904

class AstakosClient(object):

    """AstakosClient Class Implementation"""

    # ----------------------------------

    # Initialize AstakosClient Class

    # Too many arguments. pylint: disable-msg=R0913

    # Too many local variables. pylint: disable-msg=R0914

    # Too many statements. pylint: disable-msg=R0915

    def __init__(self, token, auth_url,

                 retry=0, use_pool=False, pool_size=8, logger=None):

        """Initialize AstakosClient Class

        Keyword arguments:

        token       -- user's/service's token (string)

        auth_url    -- i.e https://accounts.example.com/identity/v2.0

        retry       -- how many time to retry (integer)

        use_pool    -- use objpool for http requests (boolean)

        pool_size   -- if using pool, define the pool size

        logger      -- pass a different logger

        """

        # Get logger

        if logger is None:

            logging.basicConfig(

                format='%(asctime)s [%(levelname)s] %(name)s %(message)s',

                datefmt='%Y-%m-%d %H:%M:%S',

                level=logging.INFO)

            logger = logging.getLogger("astakosclient")

        logger.debug("Intialize AstakosClient: auth_url = %s, "

                     "use_pool = %s, pool_size = %s",

                     auth_url, use_pool, pool_size)

        # Check that token and auth_url (mandatory options) are given

        check_input("__init__", logger, token=token, auth_url=auth_url)

        # Initialize connection class

        parsed_auth_url = urlparse.urlparse(auth_url)

        conn_class = \

            scheme_to_class(parsed_auth_url.scheme, use_pool, pool_size)

        if conn_class is None:

            msg = "Unsupported scheme: %s" % parsed_auth_url.scheme

            logger.error(msg)

            raise BadValue(msg)

        # Save astakos base url, logger, connection class etc in our class

        self.retry = retry

        self.logger = logger

        self.token = token

        self.astakos_base_url = parsed_auth_url.netloc

        self.scheme = parsed_auth_url.scheme

        self.conn_class = conn_class

        # Initialize astakos api prefixes

        # API urls under auth_url

        self.auth_prefix = parsed_auth_url.path

        self.api_tokens = join_urls(self.auth_prefix, "tokens")

    def _fill_endpoints(self, endpoints):

        astakos_service_catalog = parse_endpoints(

            endpoints, ep_name="astakos_account", ep_version_id="v1.0")

        self._account_url = \

            astakos_service_catalog[0]['endpoints'][0]['publicURL']

        parsed_account_url = urlparse.urlparse(self._account_url)

        self._account_prefix = parsed_account_url.path

        self.logger.debug("Got account_prefix \"%s\"" % self._account_prefix)

        self._ui_url = \

            astakos_service_catalog[0]['endpoints'][0]['SNF:uiURL']

        parsed_ui_url = urlparse.urlparse(self._ui_url)

        self._ui_prefix = parsed_ui_url.path

        self.logger.debug("Got ui_prefix \"%s\"" % self._ui_prefix)

    def _get_value(self, s):

        assert s in ['_account_url', '_account_prefix',

                     '_ui_url', '_ui_prefix']

        try:

            return getattr(self, s)

        except AttributeError:

            self.get_endpoints()

            return getattr(self, s)

    @property

    def account_url(self):

        return self._get_value('_account_url')

    @property

    def account_prefix(self):

        return self._get_value('_account_prefix')

    @property

    def ui_url(self):

        return self._get_value('_ui_url')

    @property

    def ui_prefix(self):

        return self._get_value('_ui_prefix')

    @property

    def api_usercatalogs(self):

        return join_urls(self.account_prefix, "user_catalogs")

    @property

    def api_service_usercatalogs(self):

        return join_urls(self.account_prefix, "service/user_catalogs")

    @property

    def api_resources(self):

        return join_urls(self.account_prefix, "resources")

    @property

    def api_quotas(self):

        return join_urls(self.account_prefix, "quotas")

    @property

    def api_service_quotas(self):

        return join_urls(self.account_prefix, "service_quotas")

    @property

    def api_commissions(self):

        return join_urls(self.account_prefix, "commissions")

    @property

    def api_commissions_action(self):

        return join_urls(self.api_commissions, "action")

    @property

    def api_feedback(self):

        return join_urls(self.account_prefix, "feedback")

    @property

    def api_projects(self):

        return join_urls(self.account_prefix, "projects")

    @property

    def api_applications(self):

        return join_urls(self.api_projects, "apps")

    @property

    def api_memberships(self):

        return join_urls(self.api_projects, "memberships")

    @property

    def api_getservices(self):

        return join_urls(self.ui_prefix, "get_services")

    # ----------------------------------

    @retry_dec

    def _call_astakos(self, request_path, headers=None,

                      body=None, method="GET", log_body=True):

        """Make the actual call to Astakos Service"""

        hashed_token = hashlib.sha1()

        hashed_token.update(self.token)

        self.logger.debug(

            "Make a %s request to %s, using token with hash %s, "

            "with headers %s and body %s",

            method, request_path, hashed_token.hexdigest(), headers,

            body if log_body else "(not logged)")

        # Check Input

        if headers is None:

            headers = {}

        if body is None:

            body = {}

        # Initialize log_request and log_response attributes

        self.log_request = None

        self.log_response = None

        # Build request's header and body

        kwargs = {}

        kwargs['headers'] = copy(headers)

        kwargs['headers']['X-Auth-Token'] = self.token

        if body:

            kwargs['body'] = copy(body)

            kwargs['headers'].setdefault(

                'content-type', 'application/octet-stream')

        kwargs['headers'].setdefault('content-length',

                                     len(body) if body else 0)

        try:

            # Get the connection object

            with self.conn_class(self.astakos_base_url) as conn:

                # Log the request so other clients (like kamaki)

                # can use them to produce their own log messages.

                self.log_request = dict(method=method, path=request_path)

                self.log_request.update(kwargs)

                # Send request

                # Used * or ** magic. pylint: disable-msg=W0142

                (message, data, status) = \

                    _do_request(conn, method, request_path, **kwargs)

                # Log the response so other clients (like kamaki)

                # can use them to produce their own log messages.

                self.log_response = dict(

                    status=status, message=message, data=data)

        except Exception as err:

            self.logger.error("Failed to send request: %s" % repr(err))

            raise AstakosClientException(str(err))

        # Return

        self.logger.debug("Request returned with status %s" % status)

        if status == 400:

            raise BadRequest(message, data)

        elif status == 401:

            raise Unauthorized(message, data)

        elif status == 403:

            raise Forbidden(message, data)

        elif status == 404:

            raise NotFound(message, data)

        elif status < 200 or status >= 300:

            raise AstakosClientException(message, data, status)

        try:

            if data:

                return simplejson.loads(unicode(data))

            else:

                return None

        except Exception as err:

            msg = "Cannot parse response \"%s\" with simplejson: %s"

            self.logger.error(msg % (data, str(err)))

            raise InvalidResponse(str(err), data)

    # ----------------------------------

    # do a POST to ``API_USERCATALOGS`` (or ``API_SERVICE_USERCATALOGS``)

    #   with {'uuids': uuids}

    def _uuid_catalog(self, uuids, req_path):

        """Helper function to retrieve uuid catalog"""

        req_headers = {'content-type': 'application/json'}

        req_body = parse_request({'uuids': uuids}, self.logger)

        data = self._call_astakos(req_path, headers=req_headers,

                                  body=req_body, method="POST")

        if "uuid_catalog" in data:

            return data.get("uuid_catalog")

        else:

            msg = "_uuid_catalog request returned %s. No uuid_catalog found" \

                  % data

            self.logger.error(msg)

            raise AstakosClientException(msg)

    def get_usernames(self, uuids):

        """Return a uuid_catalog dictionary for the given uuids

        Keyword arguments:

        uuids   -- list of user ids (list of strings)

        The returned uuid_catalog is a dictionary with uuids as

        keys and the corresponding user names as values

        """

        return self._uuid_catalog(uuids, self.api_usercatalogs)

    def get_username(self, uuid):

        """Return the user name of a uuid (see get_usernames)"""

        check_input("get_username", self.logger, uuid=uuid)

        uuid_dict = self.get_usernames([uuid])

        if uuid in uuid_dict:

            return uuid_dict.get(uuid)

        else:

            raise NoUserName(uuid)

    def service_get_usernames(self, uuids):

        """Return a uuid_catalog dict using a service's token"""

        return self._uuid_catalog(uuids, self.api_service_usercatalogs)

    def service_get_username(self, uuid):

        """Return the displayName of a uuid using a service's token"""

        check_input("service_get_username", self.logger, uuid=uuid)

        uuid_dict = self.service_get_usernames([uuid])

        if uuid in uuid_dict:

            return uuid_dict.get(uuid)

        else:

            raise NoUserName(uuid)

    # ----------------------------------

    # do a POST to ``API_USERCATALOGS`` (or ``API_SERVICE_USERCATALOGS``)

    #   with {'displaynames': display_names}

    def _displayname_catalog(self, display_names, req_path):

        """Helper function to retrieve display names catalog"""

        req_headers = {'content-type': 'application/json'}

        req_body = parse_request({'displaynames': display_names}, self.logger)

        data = self._call_astakos(req_path, headers=req_headers,

                                  body=req_body, method="POST")

        if "displayname_catalog" in data:

            return data.get("displayname_catalog")

        else:

            msg = "_displayname_catalog request returned %s. " \

                  "No displayname_catalog found" % data

            self.logger.error(msg)

            raise AstakosClientException(msg)

    def get_uuids(self, display_names):

        """Return a displayname_catalog for the given names

        Keyword arguments:

        display_names   -- list of user names (list of strings)

        The returned displayname_catalog is a dictionary with

        the names as keys and the corresponding uuids as values

        """

        return self._displayname_catalog(

            display_names, self.api_usercatalogs)

    def get_uuid(self, display_name):

        """Return the uuid of a name (see getUUIDs)"""

        check_input("get_uuid", self.logger, display_name=display_name)

        name_dict = self.get_uuids([display_name])

        if display_name in name_dict:

            return name_dict.get(display_name)

        else:

            raise NoUUID(display_name)

    def service_get_uuids(self, display_names):

        """Return a display_name catalog using a service's token"""

        return self._displayname_catalog(

            display_names, self.api_service_usercatalogs)

    def service_get_uuid(self, display_name):

        """Return the uuid of a name using a service's token"""

        check_input("service_get_uuid", self.logger, display_name=display_name)

        name_dict = self.service_get_uuids([display_name])

        if display_name in name_dict:

            return name_dict.get(display_name)

        else:

            raise NoUUID(display_name)

    # ----------------------------------

    # do a GET to ``API_GETSERVICES``

    def get_services(self):

        """Return a list of dicts with the registered services"""

        return self._call_astakos(self.api_getservices)

    # ----------------------------------

    # do a GET to ``API_RESOURCES``

    def get_resources(self):

        """Return a dict of dicts with the available resources"""

        return self._call_astakos(self.api_resources)

    # ----------------------------------

    # do a POST to ``API_FEEDBACK``

    def send_feedback(self, message, data):

        """Send feedback to astakos service

        keyword arguments:

        message     -- Feedback message

        data        -- Additional information about service client status

        In case of success return nothing.

        Otherwise raise an AstakosClientException

        """

        check_input("send_feedback", self.logger, message=message, data=data)

        req_body = urllib.urlencode(

            {'feedback_msg': message, 'feedback_data': data})

        self._call_astakos(self.api_feedback, headers=None,

                           body=req_body, method="POST")

    # -----------------------------------------

    # do a POST to ``API_TOKENS`` with no token

    def get_endpoints(self):

        """ Get services' endpoints

        In case of error raise an AstakosClientException.

        """

        req_headers = {'content-type': 'application/json'}

        req_body = None

        r = self._call_astakos(self.api_tokens, headers=req_headers,

                               body=req_body, method="POST",

                               log_body=False)

        self._fill_endpoints(r)

        return r

    # --------------------------------------

    # do a POST to ``API_TOKENS`` with a token

    def authenticate(self, tenant_name=None):

        """ Authenticate and get services' endpoints

        Keyword arguments:

        tenant_name         -- user's uniq id (optional)

        It returns back the token as well as information about the token

        holder and the services he/she can access (in json format).

        The tenant_name is optional and if it is given it must match the

        user's uuid.

        In case of error raise an AstakosClientException.

        """

        req_headers = {'content-type': 'application/json'}

        body = {'auth': {'token': {'id': self.token}}}

        if tenant_name is not None:

            body['auth']['tenantName'] = tenant_name

        req_body = parse_request(body, self.logger)

        r = self._call_astakos(self.api_tokens, headers=req_headers,

                               body=req_body, method="POST",

                               log_body=False)

        self._fill_endpoints(r)

        return r

    # ----------------------------------

    # do a GET to ``API_QUOTAS``

    def get_quotas(self):

        """Get user's quotas

        In case of success return a dict of dicts with user's current quotas.

        Otherwise raise an AstakosClientException

        """

        return self._call_astakos(self.api_quotas)

    # ----------------------------------

    # do a GET to ``API_SERVICE_QUOTAS``

    def service_get_quotas(self, user=None):

        """Get all quotas for resources associated with the service

        Keyword arguments:

        user    -- optionally, the uuid of a specific user

        In case of success return a dict of dicts of dicts with current quotas

        for all users, or of a specified user, if user argument is set.

        Otherwise raise an AstakosClientException

        """

        query = self.api_service_quotas

        if user is not None:

            query += "?user=" + user

        return self._call_astakos(query)

    # ----------------------------------

    # do a POST to ``API_COMMISSIONS``

    def issue_commission(self, request):

        """Issue a commission

        Keyword arguments:

        request -- commision request (dict)

        In case of success return commission's id (int).

        Otherwise raise an AstakosClientException.

        """

        req_headers = {'content-type': 'application/json'}

        req_body = parse_request(request, self.logger)

        try:

            response = self._call_astakos(self.api_commissions,

                                          headers=req_headers,

                                          body=req_body,

                                          method="POST")

        except AstakosClientException as err:

            if err.status == 413:

                raise QuotaLimit(err.message, err.details)

            else:

                raise

        if "serial" in response:

            return response['serial']

        else:

            msg = "issue_commission_core request returned %s. " + \

                  "No serial found" % response

            self.logger.error(msg)

            raise AstakosClientException(msg)

    def issue_one_commission(self, holder, source, provisions,

                             name="", force=False, auto_accept=False):

        """Issue one commission (with specific holder and source)

        keyword arguments:

        holder      -- user's id (string)

        source      -- commission's source (ex system) (string)

        provisions  -- resources with their quantity (dict from string to int)

        name        -- description of the commission (string)

        force       -- force this commission (boolean)

        auto_accept -- auto accept this commission (boolean)

        In case of success return commission's id (int).

        Otherwise raise an AstakosClientException.

        (See also issue_commission)

        """

        check_input("issue_one_commission", self.logger,

                    holder=holder, source=source,

                    provisions=provisions)

        request = {}

        request["force"] = force

        request["auto_accept"] = auto_accept

        request["name"] = name

        try:

            request["provisions"] = []

            for resource, quantity in provisions.iteritems():

                prov = {"holder": holder, "source": source,

                        "resource": resource, "quantity": quantity}

                request["provisions"].append(prov)

        except Exception as err:

            self.logger.error(str(err))

            raise BadValue(str(err))

        return self.issue_commission(request)

    # ----------------------------------

    # do a GET to ``API_COMMISSIONS``

    def get_pending_commissions(self):

        """Get Pending Commissions

        In case of success return a list of pending commissions' ids

        (list of integers)

        """

        return self._call_astakos(self.api_commissions)

    # ----------------------------------

    # do a GET to ``API_COMMISSIONS``/<serial>

    def get_commission_info(self, serial):

        """Get Description of a Commission

        Keyword arguments:

        serial  -- commission's id (int)

        In case of success return a dict of dicts containing

        informations (details) about the requested commission

        """

        check_input("get_commission_info", self.logger, serial=serial)

        path = self.api_commissions.rstrip('/') + "/" + str(serial)

        return self._call_astakos(path)

    # ----------------------------------

    # do a POST to ``API_COMMISSIONS``/<serial>/action"

    def commission_action(self, serial, action):

        """Perform a commission action

        Keyword arguments:

        serial  -- commission's id (int)

        action  -- action to perform, currently accept/reject (string)

        In case of success return nothing.

        """

        check_input("commission_action", self.logger,

                    serial=serial, action=action)

        path = self.api_commissions.rstrip('/') + "/" + str(serial) + "/action"

        req_headers = {'content-type': 'application/json'}

        req_body = parse_request({str(action): ""}, self.logger)

        self._call_astakos(path, headers=req_headers,

                           body=req_body, method="POST")

    def accept_commission(self, serial):

        """Accept a commission (see commission_action)"""

        self.commission_action(serial, "accept")

    def reject_commission(self, serial):

        """Reject a commission (see commission_action)"""

        self.commission_action(serial, "reject")

    # ----------------------------------

    # do a POST to ``API_COMMISSIONS_ACTION``

    def resolve_commissions(self, accept_serials, reject_serials):

        """Resolve multiple commissions at once

        Keyword arguments:

        accept_serials  -- commissions to accept (list of ints)

        reject_serials  -- commissions to reject (list of ints)

        In case of success return a dict of dicts describing which

        commissions accepted, which rejected and which failed to

        resolved.

        """

        check_input("resolve_commissions", self.logger,

                    accept_serials=accept_serials,

                    reject_serials=reject_serials)

        req_headers = {'content-type': 'application/json'}

        req_body = parse_request({"accept": accept_serials,

                                  "reject": reject_serials},

                                 self.logger)

        return self._call_astakos(self.api_commissions_action,

                                  headers=req_headers, body=req_body,

                                  method="POST")

    # ----------------------------

    # do a GET to ``API_PROJECTS``

    def get_projects(self, name=None, state=None, owner=None):

        """Retrieve all accessible projects

        Arguments:

        name  -- filter by name (optional)

        state -- filter by state (optional)

        owner -- filter by owner (optional)

        In case of success, return a list of project descriptions.

        """

        filters = {}

        if name is not None:

            filters["name"] = name

        if state is not None:

            filters["state"] = state

        if owner is not None:

            filters["owner"] = owner

        req_headers = {'content-type': 'application/json'}

        req_body = (parse_request({"filter": filters}, self.logger)

                    if filters else None)

        return self._call_astakos(self.api_projects,

                                  headers=req_headers, body=req_body)

    # -----------------------------------------

    # do a GET to ``API_PROJECTS``/<project_id>

    def get_project(self, project_id):

        """Retrieve project description, if accessible

        Arguments:

        project_id -- project identifier

        In case of success, return project description.

        """

        path = join_urls(self.api_projects, str(project_id))

        return self._call_astakos(path)

    # -----------------------------

    # do a POST to ``API_PROJECTS``

    def create_project(self, specs):

        """Submit application to create a new project

        Arguments:

        specs -- dict describing a project

        In case of success, return project and application identifiers.

        """

        req_headers = {'content-type': 'application/json'}

        req_body = parse_request(specs, self.logger)

        return self._call_astakos(self.api_projects,

                                  headers=req_headers, body=req_body,

                                  method="POST")

    # ------------------------------------------

    # do a POST to ``API_PROJECTS``/<project_id>

    def modify_project(self, project_id, specs):

        """Submit application to modify an existing project

        Arguments:

        project_id -- project identifier

        specs      -- dict describing a project

        In case of success, return project and application identifiers.

        """

        path = join_urls(self.api_projects, str(project_id))

        req_headers = {'content-type': 'application/json'}

        req_body = parse_request(specs, self.logger)

        return self._call_astakos(path, headers=req_headers,

                                  body=req_body, method="POST")

    # -------------------------------------------------

    # do a POST to ``API_PROJECTS``/<project_id>/action

    def project_action(self, project_id, action, reason=""):

        """Perform action on a project

        Arguments:

        project_id -- project identifier

        action     -- action to perform, one of "suspend", "unsuspend",

                      "terminate", "reinstate"

        reason     -- reason of performing the action

        In case of success, return nothing.

        """

        path = join_urls(self.api_projects, str(project_id))

        path = join_urls(path, "action")

        req_headers = {'content-type': 'application/json'}

        req_body = parse_request({action: reason}, self.logger)

        return self._call_astakos(path, headers=req_headers,

                                  body=req_body, method="POST")

    # --------------------------------

    # do a GET to ``API_APPLICATIONS``

    def get_applications(self, project=None):

        """Retrieve all accessible applications

        Arguments:

        project -- filter by project (optional)

        In case of success, return a list of application descriptions.

        """

        req_headers = {'content-type': 'application/json'}

        body = {"project": project} if project is not None else None

        req_body = parse_request(body, self.logger) if body else None

        return self._call_astakos(self.api_applications,

                                  headers=req_headers, body=req_body)

    # -----------------------------------------

    # do a GET to ``API_APPLICATIONS``/<app_id>

    def get_application(self, app_id):

        """Retrieve application description, if accessible

        Arguments:

        app_id -- application identifier

        In case of success, return application description.

        """

        path = join_urls(self.api_applications, str(app_id))

        return self._call_astakos(path)

    # -------------------------------------------------

    # do a POST to ``API_APPLICATIONS``/<app_id>/action

    def application_action(self, app_id, action, reason=""):

        """Perform action on an application

        Arguments:

        app_id -- application identifier

        action -- action to perform, one of "approve", "deny",

                  "dismiss", "cancel"

        reason -- reason of performing the action

        In case of success, return nothing.

        """

        path = join_urls(self.api_applications, str(app_id))

        path = join_urls(path, "action")

        req_headers = {'content-type': 'application/json'}

        req_body = parse_request({action: reason}, self.logger)

        return self._call_astakos(path, headers=req_headers,

                                  body=req_body, method="POST")

    # -------------------------------

    # do a GET to ``API_MEMBERSHIPS``

    def get_memberships(self, project=None):

        """Retrieve all accessible memberships

        Arguments:

        project -- filter by project (optional)

        In case of success, return a list of membership descriptions.

        """

        req_headers = {'content-type': 'application/json'}

        body = {"project": project} if project is not None else None

        req_body = parse_request(body, self.logger) if body else None

        return self._call_astakos(self.api_memberships,

                                  headers=req_headers, body=req_body)

    # -----------------------------------------

    # do a GET to ``API_MEMBERSHIPS``/<memb_id>

    def get_membership(self, memb_id):

        """Retrieve membership description, if accessible

        Arguments:

        memb_id -- membership identifier

        In case of success, return membership description.

        """

        path = join_urls(self.api_memberships, str(memb_id))

        return self._call_astakos(path)

    # -------------------------------------------------

    # do a POST to ``API_MEMBERSHIPS``/<memb_id>/action

    def membership_action(self, memb_id, action, reason=""):

        """Perform action on a membership

        Arguments:

        memb_id -- membership identifier

        action  -- action to perform, one of "leave", "cancel", "accept",

                   "reject", "remove"

        reason  -- reason of performing the action

        In case of success, return nothing.

        """

        path = join_urls(self.api_memberships, str(memb_id))

        path = join_urls(path, "action")

        req_headers = {'content-type': 'application/json'}

        req_body = parse_request({action: reason}, self.logger)

        return self._call_astakos(path, headers=req_headers,

                                  body=req_body, method="POST")

    # --------------------------------

    # do a POST to ``API_MEMBERSHIPS``

    def join_project(self, project_id):

        """Join a project

        Arguments:

        project_id -- project identifier

        In case of success, return membership identifier.

        """

        req_headers = {'content-type': 'application/json'}

        body = {"join": {"project": project_id}}

        req_body = parse_request(body, self.logger)

        return self._call_astakos(self.api_memberships, headers=req_headers,

                                  body=req_body, method="POST")

    # --------------------------------

    # do a POST to ``API_MEMBERSHIPS``

    def enroll_member(self, project_id, email):

        """Enroll a user in a project

        Arguments:

        project_id -- project identifier

        email      -- user identified by email

        In case of success, return membership identifier.

        """

        req_headers = {'content-type': 'application/json'}

        body = {"enroll": {"project": project_id, "user": email}}

        req_body = parse_request(body, self.logger)

        return self._call_astakos(self.api_memberships, headers=req_headers,

                                  body=req_body, method="POST")

# --------------------------------------------------------------------

# parse endpoints

def parse_endpoints(endpoints, ep_name=None, ep_type=None,

                    ep_region=None, ep_version_id=None):

    """Parse endpoints server response and extract the ones needed

    Keyword arguments:

    endpoints     -- the endpoints (json response from get_endpoints)

    ep_name       -- return only endpoints with this name (optional)

    ep_type       -- return only endpoints with this type (optional)

    ep_region     -- return only endpoints with this region (optional)

    ep_version_id -- return only endpoints with this versionId (optional)

    In case one of the `name', `type', `region', `version_id' parameters

    is given, return only the endpoints that match all of these criteria.

    If no match is found then raise NoEndpoints exception.

    """

    try:

        catalog = endpoints['access']['serviceCatalog']

        if ep_name is not None:

            catalog = \

                [c for c in catalog if c['name'] == ep_name]

        if ep_type is not None:

            catalog = \

                [c for c in catalog if c['type'] == ep_type]

        if ep_region is not None:

            for c in catalog:

                c['endpoints'] = [e for e in c['endpoints']

                                  if e['region'] == ep_region]

            # Remove catalog entries with no endpoints

            catalog = \

                [c for c in catalog if c['endpoints']]

        if ep_version_id is not None:

            for c in catalog:

                c['endpoints'] = [e for e in c['endpoints']

                                  if e['versionId'] == ep_version_id]

            # Remove catalog entries with no endpoints

            catalog = \

                [c for c in catalog if c['endpoints']]

        if not catalog:

            raise NoEndpoints(ep_name, ep_type,

                              ep_region, ep_version_id)

        else:

            return catalog

    except KeyError:

        raise NoEndpoints()

# --------------------------------------------------------------------

# Private functions

# We want _do_request to be a distinct function

# so that we can replace it during unit tests.

def _do_request(conn, method, url, **kwargs):

    """The actual request. This function can easily be mocked"""

    conn.request(method, url, **kwargs)

    response = conn.getresponse()

    length = response.getheader('content-length', None)

    data = response.read(length)

    status = int(response.status)

    message = response.reason

    return (message, data, status)